Diagnostic Functions

The control module has an on board diagnostic system, Volvo Diagnostics. The control module continuously monitors itself and input and output signals in the system. By connecting the Volvo Scan Tool (ST) to the data link connector (DLC) it is possible to obtain different types of information in the form of diagnostic trouble codes (DTCs), current parameters for readings on components etc.

The diagnostics system can also be used to activate components and functions by using the Volvo Scan Tool (ST).


NOTE If it is not possible to operate the seat or access the diagnostic system, check that none of the buttons on the control panel are stuck in the down position. Carry out the procedure again with the engine of the car running. Battery voltage must be at full voltage in order for the before the on-board diagnostic (OBD) system to work. Refer to Checking Voltage and Ciommunication. Checking Supply Voltage Fault Tracing Information


On cars within the chassis range 76200 79589 (4-door) and 28100-29254 (5-door) the control module's diagnostic functions have been disabled. The Volvo Scan Tool (ST) can only be used if the existing control module is replaced with a new module. The existing control module on the cars in these chassis number ranges operate normally apart from the disabled diagnostic functions.

On a few cars within the chassis number ranges the diagnostics wiring to the control module is disconnected. When replacing the control module with a new one the diagnostics wiring must be connected to connector A to the control module in order for communication with the Volvo Scan Tool (ST) to take place.